Transport in Humans and Animals: Biology Tingkatan 4 questions

Section A: objective questions

12 marks

Choose the best answer for each question.

Why can a large multicellular organism not rely on diffusion alone to supply its cells?

Its cells have no cell membranes to let substances through
Its total surface area to volume ratio is small and most cells are far from the environment
Its cells do not need oxygen or nutrients like other cells
Diffusion can only take place in water and not in air

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A small TSA/V and long distances make diffusion too slow, so a transport system is needed.

For the teacher: Understanding, low difficulty, standard 10.1

Textbook p. 168

What is the name of the body cavity in which haemolymph bathes the cells of an insect?

Atrium
Lumen
Haemocoel
Ostium

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The haemocoel is the cavity. Ostia are the openings through which haemolymph re-enters the heart.

For the teacher: Remembering, low difficulty, standard 10.1

Textbook p. 169

Which statement about the heart chambers is correct?

Fish have four chambers
Amphibians have three chambers
Humans have three chambers
Insects have two chambers

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Fish have two chambers, amphibians three (two atria, one ventricle) and humans four.

For the teacher: Understanding, low difficulty, standard 10.1

Textbook p. 171

Which valve lies between the left atrium and the left ventricle?

Tricuspid valve
Semilunar valve
Pulmonary valve
Bicuspid valve

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The bicuspid valve (two flaps) is on the left; the tricuspid valve is on the right.

For the teacher: Remembering, low difficulty, standard 10.2

Textbook p. 174

Which vessel carries oxygenated blood?

Pulmonary artery
Vena cava
Pulmonary vein
Coronary vein

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The pulmonary vein brings oxygenated blood from the lungs to the left atrium. The others carry deoxygenated blood.

For the teacher: Understanding, medium difficulty, standard 10.2

Textbook p. 174

Which feature is found in veins but not in arteries?

A thick elastic wall
Valves along the vessel
A very small lumen
Very high blood pressure

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Veins have valves to keep blood moving one way at low pressure.

For the teacher: Understanding, low difficulty, standard 10.2

Textbook p. 179

Where is the main pacemaker of the heart?

Wall of the right atrium
Apex of the heart
Wall of the left ventricle
Septum

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The sinoatrial node is in the right atrium wall.

For the teacher: Remembering, low difficulty, standard 10.3

Textbook p. 181

In which order do the electrical impulses of one heartbeat travel?

SA node, bundle of His, AV node, Purkinje fibres
AV node, SA node, bundle of His, Purkinje fibres
Purkinje fibres, bundle of His, AV node, SA node
SA node, AV node, bundle of His, Purkinje fibres

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SA node, atria, AV node, bundle of His, Purkinje fibres, ventricles.

For the teacher: Applying, medium difficulty, standard 10.3

Textbook p. 181

Which substance catalyses the change of fibrinogen to fibrin?

Thrombin
Thrombokinase
Prothrombin
Heparin

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Thrombin is an enzyme that catalyses fibrinogen to fibrin. Prothrombin is its inactive form.

For the teacher: Understanding, low difficulty, standard 10.4

Textbook p. 183

A patient has blood group AB. From which donors can the patient safely receive blood?

AB only
A and AB only
B and O only
A, B, AB and O

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Group AB has no antibodies in the serum, so every ABO group is compatible.

For the teacher: Applying, medium difficulty, standard 10.5

Textbook p. 185

Why does tissue fluid contain no erythrocytes?

They are destroyed in the capillary
They are too large to pass out of the capillary wall
They are filtered by the lymph nodes
They stick to the endothelium

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Erythrocytes, platelets and plasma proteins are too large to leave the capillaries.

For the teacher: Understanding, medium difficulty, standard 10.7

Textbook p. 189

A patient confined to bed for a long time develops swollen legs. What is the most likely reason?

Tissue fluid is not returned to the blood because there is little muscle contraction
Too many erythrocytes are made in the bone marrow
Blood clots dissolve too quickly inside the veins
The bicuspid valve is leaking into the left atrium

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Little skeletal muscle movement slows lymph flow, so tissue fluid builds up (oedema).

For the teacher: Applying, medium difficulty, standard 10.8

Textbook p. 193

Section B: structured questions

27 marks

Answer all questions.

Compare the circulatory systems of fish and humans.

[2 marks] (a)How many chambers does the heart of each have?

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Fish: two chambers (one atrium and one ventricle) [1]1
Human: four chambers (two atria and two ventricles) [1]1

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[2 marks] (b)State the type of circulation in fish and in humans, and how many times blood passes through the heart in one complete cycle.

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Fish: single circulation, once [1]1
Humans: double circulation, twice [1]1

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[1 mark] (c)Why is the human circulatory system called a complete double circulation?

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Oxygenated and deoxygenated blood do not mix because the septum separates the two sides1

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For the teacher: Understanding, low difficulty, standard 10.1

Textbook p. 172

A red blood cell is a biconcave disc with no nucleus.

[1 mark] (a)State the pigment in the red blood cell that carries oxygen.

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Haemoglobin1

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[2 marks] (b)Explain how the shape and lack of nucleus help the cell to carry oxygen.

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Biconcave shape gives a large TSA/V for gas exchange [1]1
No nucleus leaves more space for haemoglobin [1]1

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[2 marks] (c)A person with a low number of erythrocytes feels tired easily. Explain why.

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Less oxygen is carried to the tissues [1]1
Less aerobic respiration, so less energy is released [1]1

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For the teacher: Understanding, low difficulty, standard 10.2

Textbook p. 176

The sinoatrial node starts each heartbeat.

[1 mark] (a)Where is the sinoatrial node found?

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In the wall of the right atrium1

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[1 mark] (b)The heart is described as myogenic. What does this mean?

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The cardiac muscle contracts and relaxes by itself without nerve impulses1

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[2 marks] (c)Name the structures that carry impulses from the atrioventricular node to the apex of the heart.

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Bundle of His [1]1
Purkinje fibres [1]1

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[1 mark] (d)Explain what causes the second heart sound, dub.

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The semilunar valves close at the base of the aorta and pulmonary artery1

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For the teacher: Remembering, low difficulty, standard 10.3

Textbook p. 181

An Rh-negative mother and an Rh-positive father have two Rh-positive children. The first child is healthy but the second child dies before birth.

[1 mark] (a)Name the antibody that harms the second child.

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Anti-D (Rhesus) antibody1

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[3 marks] (b)Explain why the first child was not harmed but the second was.

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Near the first birth, foetal blood cells with antigen D enter the mother's blood [1]1
The mother makes anti-D antibodies, too few to harm the first child but they stay in her blood [1]1
In the second pregnancy the antibodies cross the placenta and destroy the red blood cells of the foetus [1]1

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[1 mark] (c)Suggest how this problem can be prevented.

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Give the mother anti-Rhesus globulin after the first pregnancy to stop anti-D formation1

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For the teacher: Applying, high difficulty, standard 10.5

Textbook p. 186

A patient has swollen legs because a lymphatic vessel is blocked by parasitic worms.

[2 marks] (a)Name the worm and the disease it causes.

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Brugia [1]1
Lymphatic filariasis [1]1

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[2 marks] (b)Explain why the legs swell.

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Tissue fluid is not returned to the blood through the lymphatic vessel [1]1
It accumulates in the intercellular spaces (oedema) [1]1

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[2 marks] (c)State two other functions of the lymphatic system.

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Any 2 points

Transports fats and fat-soluble substances from the lacteals [1 mark each]1
Body defence: lymph nodes make and store lymphocytes [1 mark each]1
Returns excess tissue fluid to the blood to keep the volume and pressure of blood normal [1 mark each]1

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[1 mark] (d)State one difference between lymph and blood.

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Lymph has no plasma protein, erythrocytes or platelets; blood has them1

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For the teacher: Understanding, medium difficulty, standard 10.8

Textbook p. 193

Section A: objective questions

Question 1

Question 2

Question 3

Question 4

Question 5

Question 6

Question 7

Question 8

Question 9

Question 10

Question 11

Question 12

Section B: structured questions

Question 13

Question 14

Question 15

Question 16

Question 17